A Synchro is a person who practices the sport Synchronized Swimming. Synchros are usually female, who can be sporty but at the same time sexy. They work really hard to be the best that they can be, and because of that they all have smokin hot bodies. Most synchros also have really hot faces, so they're the best of both worlds.

Me: Wow did you see that synchro over there?
Chris: Yeah she was smokin! She must practice a lot! Wouldn't it be great to be dating a synchro?
Me:Yeah, it would.